阅读说明：本技术 用于砂岩地层的化学增产液及增产方法 (Chemical production increasing liquid for sandstone stratum and production increasing method ) 是由 李亭 于 2021-09-15 设计创作，主要内容包括：本发明公开了一种用于砂岩地层的化学增产液及增产方法。该化学增产液按所述化学增产液的总重量为100重量份计,所述化学增产液按重量份包括以下组分：酸液包裹剂0.5-2.5重量份、增粘剂2.0-5.0重量份、起泡剂0.8-1.2重量份、稳泡剂0.2-0.5重量份、表面活性剂0.1-0.3重量份、缓蚀剂0.2-0.5重量份,其余为水；所述酸液包裹剂为改性的环糊精,所述改性的环糊精的改性方法为：对环糊精分子洞外表面的醇羟基进行醚化和/或酯化反应,使环糊精分子洞外表面具有一定的包裹携带能力。本增产方法通过在常规土酸中添加所述用于砂岩地层的化学增产液,利用各组分之间的协同作用,能够显著降低酸岩反应速度,增大酸化增产半径,从而起到大幅度增加采油产量的作用。(The invention discloses a chemical production increasing liquid for a sandstone stratum and a production increasing method. The chemical yield increasing liquid comprises the following components in parts by weight, based on 100 parts by weight of the total weight of the chemical yield increasing liquid: 0.5-2.5 parts of acid liquid wrapping agent, 2.0-5.0 parts of tackifier, 0.8-1.2 parts of foaming agent, 0.2-0.5 part of foam stabilizer, 0.1-0.3 part of surfactant, 0.2-0.5 part of corrosion inhibitor and the balance of water; the acid liquor wrapping agent is modified cyclodextrin, and the modification method of the modified cyclodextrin comprises the following steps: and (3) carrying out etherification and/or esterification reaction on alcoholic hydroxyl on the outer surface of the cyclodextrin molecule hole, so that the outer surface of the cyclodextrin molecule hole has certain wrapping and carrying capacity. The yield increasing method can remarkably reduce the reaction speed of acid rock and increase the acidification yield increasing radius by adding the chemical yield increasing liquid for the sandstone stratum into the conventional earth acid and utilizing the synergistic effect among the components, thereby playing the role of greatly increasing the oil production yield.)

1. A chemical stimulation fluid for a sandstone formation, comprising: the chemical yield increasing liquid comprises the following components in parts by weight, based on 100 parts by weight of the total weight of the chemical yield increasing liquid: 0.5-2.5 parts of acid liquid wrapping agent, 2.0-5.0 parts of tackifier, 0.8-1.2 parts of foaming agent, 0.2-0.5 part of foam stabilizer, 0.1-0.3 part of surfactant, 0.2-0.5 part of corrosion inhibitor and the balance of water;

the acid liquor wrapping agent is modified cyclodextrin, and the modification method of the modified cyclodextrin comprises the following steps: the cyclodextrin introduces a modifying group under the condition of keeping the basic structure of the large ring unchanged, and the alcohol hydroxyl on the outer surface of the cyclodextrin molecular hole is subjected to etherification and/or esterification reaction, so that the outer surface of the cyclodextrin molecular hole has certain wrapping and carrying capacity.

2. The chemical stimulation fluid for sandstone formations according to claim 1, wherein: 1.5-2.0 parts of acid liquid wrapping agent, 4.0-5.0 parts of tackifier, 0.8-1.0 part of foaming agent, 0.4-0.5 part of foam stabilizer, 0.1-0.2 part of surfactant, 0.2-0.3 part of corrosion inhibitor and the balance of water.

3. A chemical stimulation fluid for sandstone formations according to claim 1 or 2, characterized in that: the tackifier is selected from hydroxyethyl cellulose, polyacrylamide, carboxymethyl cellulose and polyacrylate.

4. A chemical stimulation fluid for sandstone formations according to claim 3, characterized in that: the foaming agent is selected from sodium n-dodecyl sulfonate, ethylene oxide and trimethyl hexadecyl ammonium bromide.

5. The chemical stimulation fluid for sandstone formations according to claim 4, wherein: the foam stabilizer is selected from alkylolamide, fatty alcohol-polyoxyethylene ether sodium sulfate and lauryl sodium sulfate.

6. The chemical stimulation fluid for sandstone formations according to claim 5, wherein: the surfactant is selected from alkyl benzene carboxylate, alkyl sulfate, alkyl sulfonate and polyethylene glycol.

7. The chemical stimulation fluid for sandstone formations according to claim 6, wherein: the corrosion inhibitor is alkylamine.

8. The chemical stimulation fluid for sandstone formations according to claim 2, wherein: 2.0 parts of acid liquid wrapping agent, 4.0 parts of tackifier, 1.0 part of foaming agent, 0.4 part of foam stabilizer, 0.2 part of surfactant, 0.3 part of corrosion inhibitor and the balance of water.

9. A stimulation method of a chemical stimulation fluid for sandstone formations according to claims 1-8, characterized by comprising the following steps: and then, pouring the earth acid into the prepared chemical yield increasing liquid, mixing uniformly, and injecting the mixture into a petroleum production shaft.

10. A stimulation method for a chemical stimulation fluid for sandstone formations according to claim 9, characterized in that: the soil acid comprises 15% of hydrochloric acid and 3% of hydrofluoric acid, and the balance of water; the purity of the hydrochloric acid is 31 percent, and the purity of the hydrofluoric acid is 40 percent.

Technical Field

The invention relates to the technical field of oil exploitation, in particular to a chemical production increasing liquid for a sandstone stratum and a production increasing method.

Background

In the development of hydrocarbon reservoirs, there are from drilling out of oil formations to cementing, perforating, testing, workover, coring and stimulation procedures. In conventional sandstone formations, oil recovery stimulation is often performed by acidizing, i.e., acidizing a carbonate reservoir with an earth acid (a mixture of hydrochloric acid and hydrofluoric acid). Because the mineral composition in the sandstone is relatively complex, the acidification yield-increasing effect is very limited. After the earth acid is injected into the stratum, the hydrochloric acid firstly dissolves the carbonate, a large amount of calcium ions can be separated out, and the hydrofluoric acid captures the calcium ions to form calcium fluoride precipitate.

The clay mineral cannot be dissolved due to the advanced consumption of hydrofluoric acid, so that the problem of stratum pollution caused by the clay mineral is difficult to solve; in addition, the mineral dissolving capacity and reaction speed of the hydrochloric acid and the hydrofluoric acid are different, so that the problem of contradiction of using acid that the pressure does not drop and rise after acidification is brought; in addition, because the acid rock reaction speed is high and is almost completed at the moment when the acid contacts with the formation rock, the effective acting distance of the acid liquid is short, and the acid liquid is only limited to the area near a production well bore, so that the yield increase amplitude after acidification is small, the yield stabilizing time is short, and the existing acidification mode needs to be improved.

Disclosure of Invention

The first purpose of the invention is to overcome the defects of the prior art and provide a chemical yield increasing liquid for sandstone formations, which reduces the reaction speed of acid rocks, increases the acidification radius, improves the liquid supply capacity of the formations and improves the acidification yield increasing effect.

A second object of the invention is to provide a method for stimulating a chemical stimulation fluid for a sandstone formation.

The first object of the invention is achieved by the following measures: a chemical stimulation fluid for a sandstone formation, which comprises the following components in parts by weight, based on 100 parts by weight of the total weight of the chemical stimulation fluid: 0.5-2.5 parts of acid liquid wrapping agent, 2.0-5.0 parts of tackifier, 0.8-1.2 parts of foaming agent, 0.2-0.5 part of foam stabilizer, 0.1-0.3 part of surfactant, 0.2-0.5 part of corrosion inhibitor and the balance of water;

the acid liquor wrapping agent is modified cyclodextrin, and the modification method of the modified cyclodextrin comprises the following steps: the cyclodextrin introduces a modifying group under the condition of keeping the basic structure of the large ring unchanged, and the alcohol hydroxyl on the outer surface of the cyclodextrin molecular hole is subjected to etherification and/or esterification reaction, so that the outer surface of the cyclodextrin molecular hole has certain wrapping and carrying capacity.

In the technical scheme, the acid liquid wrapping agent is 1.5-2.0 parts by weight, the tackifier is 4.0-5.0 parts by weight, the foaming agent is 0.8-1.0 part by weight, the foam stabilizer is 0.4-0.5 part by weight, the surfactant is 0.1-0.2 part by weight, the corrosion inhibitor is 0.2-0.3 part by weight, and the balance is water.

In the above technical scheme, the tackifier is selected from hydroxyethyl cellulose, polyacrylamide, carboxymethyl cellulose and polyacrylate.

In the technical scheme, the foaming agent is selected from sodium n-dodecyl sulfonate, ethylene oxide and trimethyl hexadecyl ammonium bromide.

In the technical scheme, the foam stabilizer is selected from alkylolamide, fatty alcohol-polyoxyethylene ether sodium sulfate and lauryl sodium sulfate.

In the above technical scheme, the surfactant is selected from alkyl benzene carboxylate, alkyl sulfate, alkyl sulfonate and polyethylene glycol.

In the technical scheme, the corrosion inhibitor is alkylamine.

In the technical scheme, the acid liquid wrapping agent is 2.0 parts by weight, the tackifier is 4.0 parts by weight, the foaming agent is 1.0 part by weight, the foam stabilizer is 0.4 part by weight, the surfactant is 0.2 part by weight, the corrosion inhibitor is 0.3 part by weight, and the balance is water.

The second object of the invention is achieved by the following measures: a stimulation method of a chemical stimulation fluid for a sandstone formation, comprising the steps of: and then, pouring the earth acid into the prepared chemical yield increasing liquid, mixing uniformly, and injecting the mixture into a petroleum production shaft.

In the technical scheme, the earth acid comprises 15% of hydrochloric acid and 3% of hydrofluoric acid, and the balance of water; the purity of the hydrochloric acid is 31 percent, and the purity of the hydrofluoric acid is 40 percent.

The invention has the advantages that:

1. the acid liquid wrapping agent for the chemical yield increasing liquid of the sandstone stratum, provided by the invention, can wrap the earth acid, avoid the advanced consumption of hydrofluoric acid, and is beneficial to effectively dissolving and removing clay minerals by the hydrofluoric acid, so that the problem of stratum pollution caused by the clay minerals is solved; meanwhile, the acid solution wrapping agent wraps the hydrochloric acid and the hydrofluoric acid, so that the reaction speed of the hydrochloric acid and the hydrofluoric acid for dissolving minerals is slowed, and the acid using contradiction that the pressure does not drop and rise after acidification is avoided; the acid liquor wrapping agent prevents the earth acid from being in quick contact with the stratum rock, and the earth acid is released after being carried to a longer distance, so that the reaction time of the acid liquor and the rock is delayed, and the distance and the area for increasing the yield of the reconstruction are increased.

2. The tackifier, the foaming agent and the foam stabilizer in the chemical stimulation fluid generate a large amount of foams in the flowing process of the acid fluid, so that the acid fluid is prevented from rapidly entering large pores and large flowing channels, and is forced to enter small pores and flowing channels, thereby playing a role in diverting the acid fluid, promoting the acid fluid to be uniformly conveyed to the stratum around a shaft and achieving the purpose of uniform acidification; in addition, the surfactant in the chemical yield increasing liquid can obviously reduce the oil-water interfacial tension, is beneficial to acid liquor flowback, and improves the yield increasing effect.

Therefore, the chemical yield increasing liquid for the sandstone formation can realize the effects of obviously reducing the reaction speed with acid rock and increasing the acidification yield increasing radius by utilizing the synergistic effect between each component and the earth acid, thereby greatly increasing the oil extraction yield.

Drawings

FIG. 1 is a three-dimensional ring structure of a prior art cyclodextrin molecule;

figure 2 is a three-dimensional ring structure of a modified cyclodextrin molecule.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the accompanying tables and drawings, which are not intended to limit the present invention, but are merely exemplary. And the advantages of the present invention will become more apparent and readily appreciated by reference to the following description. In addition, the technical features mentioned in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other, and the amounts used in the present application are all parts by weight.

The invention relates to a chemical yield increasing liquid for a sandstone stratum, which comprises the following components in parts by weight based on 100 parts by weight of the total weight of the chemical yield increasing liquid: 0.5-2.5 parts of acid liquid wrapping agent, 2.0-5.0 parts of tackifier, 0.8-1.2 parts of foaming agent, 0.2-0.5 part of foam stabilizer, 0.1-0.3 part of surfactant, 0.2-0.5 part of corrosion inhibitor and the balance of water.

The acid liquor wrapping agent is modified cyclodextrin, and the modification method of the modified cyclodextrin comprises the following steps: the cyclodextrin introduces a modifying group under the condition of keeping the basic structure of the large ring unchanged, and the alcohol hydroxyl on the outer surface of the cyclodextrin molecular hole is subjected to etherification and/or esterification reaction, so that the outer surface of the cyclodextrin molecular hole has certain wrapping and carrying capacity.

The preferred embodiments of the present invention are as follows: 1.5-2.0 parts of acid liquid wrapping agent, 4.0-5.0 parts of tackifier, 0.8-1.0 part of foaming agent, 0.4-0.5 part of foam stabilizer, 0.1-0.2 part of surfactant, 0.2-0.3 part of corrosion inhibitor and the balance of water.

Such tackifiers include, but are not limited to, hydroxyethyl cellulose, polyacrylamide, carboxymethyl cellulose, and polyacrylate salts.

Such blowing agents include, but are not limited to, sodium n-dodecylsulfate, ethylene oxide, trimethylhexadecylammonium bromide.

The foam stabilizer includes, but is not limited to, alkylolamide, sodium fatty alcohol-polyoxyethylene ether sulfate, and sodium dodecyl sulfate.

The surfactants include, but are not limited to, alkyl benzene carboxylates, alkyl sulfates, alkyl sulfonates, polyethylene glycols.

The corrosion inhibitor is alkylamine.

A more preferred embodiment of the invention for use in a chemical stimulation fluid for sandstone formations is as follows: 2.0 parts by weight of acid liquid wrapping agent, 4.0 parts by weight of tackifier, 1.0 part by weight of foaming agent, 0.4 part by weight of foam stabilizer, 0.2 part by weight of surfactant, 0.3 part by weight of corrosion inhibitor and the balance of water (embodiment 8 of the invention).

A stimulation method of a chemical stimulation fluid for a sandstone formation, comprising the steps of: and then, pouring the earth acid into the prepared chemical yield increasing liquid, mixing uniformly, and injecting the mixture into a petroleum production shaft.

The soil acid comprises 15% of hydrochloric acid and 3% of hydrofluoric acid, and the balance of water; the purity of the hydrochloric acid is 31 percent, and the purity of the hydrofluoric acid is 40 percent.

As shown in fig. 1, in the above technical solution, cyclodextrin (CD for short) molecules have a slightly tapered hollow cylindrical three-dimensional ring structure, and when the structure contains 6D-glucose molecules, the structure is α -cyclodextrin; when the structure contains 7D-glucose molecules, the D-glucose molecule is beta-cyclodextrin; when the structure contains 8D-glucose molecules, the D-glucose molecule is gamma-cyclodextrin. In the cavity structure of the cyclodextrin molecule, the outer large open end is composed of secondary hydroxyl groups of C2 and C3, the smaller open end is composed of primary hydroxyl group of C6, the cyclodextrin molecule has hydrophilicity, and a hydrophobic region is formed in the cavity due to the shielding effect of C-H bonds.

The modified cyclodextrin is characterized in that a modifying group is introduced under the condition of keeping the basic structure of the cyclodextrin macrocycle unchanged, and chemical modification reactions such as etherification, esterification and the like are carried out on alcoholic hydroxyl on the outer surface of a cyclodextrin molecule cavity, so that the outer surface of the cyclodextrin molecule cavity has a certain capacity of wrapping and carrying earth acid. The stereo-ring structure of the modified cyclodextrin is shown in figure 2, wherein A is a hydroxide group and D is a nitrogen-hydrogen group.

The chemical yield increasing liquid for the sandstone formation and the earth acid in the technical scheme act together to perform a core displacement experiment. The experimental procedure was as follows:

step 1), firstly, using deionized water to perform core displacement, and determining the permeability of the core before the core displacement;

step 2) secondly, respectively using the earth acid (as a comparative experiment) and the chemical yield increasing liquid and the earth acid mixed liquid in the invention to perform core displacement;

and 3) finally, using deionized water for displacement, determining the permeability of the rock core after the displacement, and determining the yield increasing effect by comparing the permeability before and after the acid liquor displacement.

The specific embodiment is as follows:

table 1 shows the components and ratios of the chemical stimulation fluids of examples 1-12;

TABLE 1 chemical yield-increasing liquid compositions and proportioning table

Table 2 is a table of data for performing the core displacement experiments according to examples 1 to 12 and comparative examples of the present invention, wherein the core displacement experiments were performed by using only cloric acid in the comparative examples.

Table 2 example and comparative example core displacement experiments

As can be seen from table 2: if the chemical stimulation fluid is used alone, the core permeability of sandstone 1, sandstone 2, and sandstone 3 is improved by about several tens of times; if the earth acid is used independently, the core permeability of sandstone 1, sandstone 2 and sandstone 3 is improved by about ten times; if the chemical stimulation fluid and the earth acid are used simultaneously, the core permeability of sandstone 1, sandstone 2 and sandstone 3 is improved by more than one thousand times, wherein the chemical stimulation fluid and the earth acid in example 8 are used simultaneously, and the core permeability of sandstone 1, sandstone 2 and sandstone 3 is the highest.

From the viewpoint of comprehensive properties, examples 5,6,7 and 8 are preferred examples, and example 8 is the best example.

Through the comparative experiment, the chemical yield increasing liquid or the soil acid which is singly used has a certain yield increasing effect, and the permeability is increased to a certain degree; however, if the chemical yield-increasing liquid and the earth acid are used comprehensively, the yield-increasing effect is very obvious, and the permeability can be improved by thousands of times. The chemical yield increasing liquid provided by the invention is proved to have very good function, and the yield increasing effect is considerable if the chemical yield increasing liquid is applied to an actual production field.

Other parts not described in detail are prior art.